In 2004, I asked Merriam-Webster the following question. Assistant Editor, Kory L. Stamper, replied as follows.

Q: If I were to say that the title of this e-mail is “titled. entitled,” would I say it is entitled or titled as such?

A: It would be correct to use either “entitled” or “titled” in this way (“a book entitled Fury,” “a lecture titled “Democratic Leanings in Current Thought”). Our own Dictionary of English Usage notes:

Sources as diverse as Emily Post 1927 and Bremner 1980 have expressed disapproval of using entitled to mean “titled.” However, this well-established usage has been common for over 500 years and is the older of the two senses

Postscript: In Writing for Time (Time Inc. Magazine Company, 1990), Jesse Birnbaum and the editors of Time magazine say that entitled is

fine, when referring to a legitimate claim; not so when the word is followed by the name of a book, story, essay, paper, movie, TV show, etc. In such cases, say titled or called. In many instances, the term can be omitted: “The movie Ghostbusters opens in September” (42).